A rare second meeting in a year of the rubber-stamp parliament, the Supreme People's Assembly, closed on Tuesday without mention of the reforms, according to South Korea's Yonhap news agency. North Korea often delays major announcements.

It came amid talk that the youngest Kim to rule the impoverished North is considering reforms to boost the economy.

"They can keep and sell in the market about 30- 50 per cent of their harvest depending on the region," the source said.

It was impossible to verify the plan independently in North Korea, one of the world's most closed states.

North Korea experienced a devastating famine in the 1990s from which its economy has not recovered, and a third of its population is malnourished, according to UN estimates.

The country needs about five million tonnes of grain and potatoes to feed its people and since the early 1990s its annual harvest has been 3.5-4.7 million tonnes, according to most observers.

Experts in South Korea believe the North desperately needs fertiliser to boost yields.

The country's soil has been degraded by erosion due to poor farming techniques, they say.